2.3. Conciseness and number of claims

Pursuant to Art. 84 EPC claims must not only be clear, but also concise. In a number of cases this has been interpreted as requiring claims to be concise both individually and in their entirety (see e.g. T 79/91 and T 246/91). The examination of these requirements depends on the specific facts of the case (see also T 596/97, T 993/07). In T 1296/19 the board considered that using two groups, both denoting the same substituent (3-methylbutyl), in the same list resulted in a lack of conciseness as regards the definition of R¹. The fact that the definition of R¹ was clear did not necessarily mean that the claim containing this definition was concise. In T 1152/21 the board found that, if the term "about" associated with a specific temperature or a specific time was intended to cover measurement errors, it was superfluous and the claim was not concise.

A Markush formula is the most concise means of defining a class of chemical compounds in a claim (T 1020/98). The examining division had held that "formulating claims in a style that makes routine tasks in substantive examination unnecessarily difficult" was a contravention of Art. 84 EPC 1973. However, there is no legal basis in the EPC for a request to restrict the content of an independent claim so that substantive examination can be carried out with greater ease and less effort.

Regarding lack of conciseness because of a superfluous claim, see e.g. T 988/02.

In T 1882/12 the board pointed out that R. 43(3) EPC neither prohibited including optional features in a claim nor made it mandatory to draft a separate dependent claim for each particular embodiment to be cited in the claims.

Whilst R. 43(2) EPC provides for a restriction in the number of independent claims per category, there is no equivalent limit on the number of dependent claims or claims concerning a particular embodiment of an invention (R. 43(3) and (4) EPC). R. 43(5) EPC provides that the number of claims shall be reasonable with regard to the nature of the invention claimed.